I have created a solution for webservices . I have attached it as module to the main solution . I have kept webservices here . I am launching the module solution as headless client . But still restful webservices not working .

You do not need to start the headless client. Servoy will take care of it. Just make sure the webservice solution is the main solution, or at the mimimun included in the module list of the current solution.Next use a tool to consume the webservice. I use Postman for this, but you could also use cURL or a simple webpage (PHP or angular)

You mean your main solution is using db_A, and your webservice is using db_B?That should not be an issue as long as both databases are active in your developer. And you have added the webservice as a module to your main solution.

But maybe you can tell a bit more about your use-case. What is your webservice supposed to do?